The diagnostic value of serum leptin monitoring and its correlation with tumor necrosis factor-alpha in critically ill patients: a prospective observational study

Introduction: Severe infection and sepsis are common causes of morbidity and mortality. Early diagnosis in critically ill patients is important to reduce these complications. The present study was conducted to determine the role of serum leptin at early diagnosis and differentiation between patients with manifestations of systemic inflammatory response syndrome (SIRS) and those with sepsis in patients suffering from a broad range of diseases in the intensive care unit (ICU) and its correlation with other biomarkers, such as C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha). Methods: One hundred and six adult ICU patients were observed. CRP, leptin, IL-6 and TNF-alpha were compared among the following groups: sepsis group (n = 40), SIRS group (n = 34) and non-SIRS group (n = 32). Patients were classified into these groups at the time of blood analysis for these biomarkers. Results: Non-significant differences were observed among patients in different groups regarding biomarkers on the day of ICU admission. On the second day of ICU admission, significant elevation of leptin, IL-6 and TNF-alpha occurred in the SIRS and sepsis groups. Delayed elevation of CRP started on the fourth day of ICU admission in patients with sepsis. At the end of the first week, only CRP level was elevated in septic patients. Conclusions: Serum leptin correlates well with serum level of IL-6 and TNF-alpha. Leptin helps to differentiate SIRS from non-SIRS patients. CRP is a classic marker of sepsis but is of late onset.